3.8l FVD P&C kit for my Turbo - Help
 

Hi
I bought a FVD 3.8l for my 964 Turbo... on ebay.

However this was a long time ago now and I have just started to look at them. The document says the CR is 11.4:1 !
If its true (ebay said they were for the turbo) can I have the pistons machined to my desired ratio (7.5 or 8:1) ? Or is there not enough to come off. I assume the cylinders are all the same length for NA and Turbo.

Thanks for any help
http://forums.pelicanparts.com/uploa...1158603423.jpg

Might want to post this in the engine building forum, instead.

Doug

Typically, The 964 OEM pistons have enough "meat" on them to machine them down to 8.0:1. Protomotive does that all the time for their 964 big HP turbo conversions.

I don't know about the FVD stuff though.

Do you have the equip. to measure the crown thickness? You want to know distance to top ring. You need to know thinnest area. I would consult someone on quench area after milling the crowns down. You might also have the bowls worked when the heads are freshened. The base gaskets could be bumped a little. As Merv has mentioned you may take a few ideas from Protomotive and look at running turbo head gaskets too. These are all areas to look into to compensate for any restrictions in the piston reduction.

Another idea that I would consult someone in if your spending FVD prices is custom length connecting rods. You probably are not going to run the stock small rod bolt rods anyhow, correct?

I'm most concerned with shape of flame front and quench area with milling the pistons down 3 full points and then adding boost to a rather large bore!

I'd call FVD in Floirda and talk to them - that sure looks like a machined pistons.

Thanks for the help.
The real deal is I have a twin turbo 3.6 (converted from a NA one) as well and I wanted them to go in it.
I need to contact FVD I think because the box the pistons come says BI turbo on it! and I think the 993TT pistons had a dome in there.
It works out the CR on the document but uses a 60cc head chamber volume- but I read somewhere the NA 964 heads are 90cc in that case it would bring the CR to 8:1.

I dont have any specfic tools. I guess ill see what FVD suggest!